840373309 has 2 divisors, whose sum is σ = 840373310. Its totient is φ = 840373308.

The previous prime is 840373307. The next prime is 840373319. The reversal of 840373309 is 903373048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 560647684 + 279725625 = 23678^2 + 16725^2 .

It is a cyclic number.

It is not a de Polignac number, because 840373309 - 2¹ = 840373307 is a prime.

Together with 840373307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840373307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420186654 + 420186655.

It is an arithmetic number, because the mean of its divisors is an integer number (420186655).

Almost surely, 2^840373309 is an apocalyptic number.

It is an amenable number.

840373309 is a deficient number, since it is larger than the sum of its proper divisors (1).

840373309 is an equidigital number, since it uses as much as digits as its factorization.

840373309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 37.

The square root of 840373309 is about 28989.1929691049. The cubic root of 840373309 is about 943.6785497769.

The spelling of 840373309 in words is "eight hundred forty million, three hundred seventy-three thousand, three hundred nine".